After weeks of escalating tensions and sporadic bursts of violence, forces opposed to President Pierre Nkurunziza launched a coordinated attack against military sites across Burundi’s capital today. Reuters:

Gunmen attacked military sites in Burundi’s capital on Friday and 12 of the assailants were killed while 20 were arrested after heavy fighting, the army said.

Soldiers told Reuters at least five of their number were also killed, but an official army spokesman said they were only wounded in the latest flare-up in a nation Western powers fear may be sliding back into ethnic conflict.The sound of firing echoed across the capital, Bujumbura, through Friday after heavy gunfire and blasts erupted in the early hours. Residents said streets were empty and police were out in force at a time when people normally head to work.

Though the conflict has thus far remained anchored in political opposition to Nkurunziza’s constitutionally questionable third term in office, some Africa watchers fear the re-emergence of ethnic violence between Tutsis and Hutus. Ethnic divisions are important for understanding what’s happening in Burundi. It’s not clear that the situation there will escalate into full-scale genocide, but there are many shades of ugly, and the country may be primed for at least one of them.

Instability in Burundi isn’t an isolated event in Africa, of course. Next door, eastern Congo is embroiled in a conflict that has displaced millions—and that instability in turn affects Burundi. The Council on Foreign Relations has published an excellent backgrounder on the subject. Read the whole thing.